The bug
When a dispenser dispenses a Bucket of Tadpole above or below a dimension, the dispenser dispenses the Bucket of Tadpole item, rather than a tadpole. All other bucketed mobs dispense the entity when being dispensed above or below a dimension.
How to reproduce
Enter the Nether
Run the command:
/setblock ~ 255 ~ dispenser[facing=up]
Run the command:
/tp @s ~ 256 ~
Place a Bucket of Axolotl in the dispenser, and activate the dispenser with a button
✔ An axolotl is spawned above the dispenserPlace a Bucket of Tadpole in the dispenser, and activate the dispenser with a button
❌ The Bucket of Tadpole item is dispensed, rather than the tadpole
Expected behavior
The tadpole would be spawned when activating the dispenser.
Actual behavior
The Bucket of Tadpole is dropped when activating the dispenser.
This happens in all dimensions, not just in the Nether.